# KeyNested

- `KeyNested(string $name)`
- `KeyNested(string $name, Validatable $rule)`
- `KeyNested(string $name, Validatable $rule, bool $mandatory)`

Validates an array key or an object property using `.` to represent nested data.

Validating keys from arrays or `ArrayAccess` instances:

```php
$array = [
    'foo' => [
        'bar' => 123,
    ],
];

v::keyNested('foo.bar')->validate($array); // true
```

Validating object properties:

```php
$object = new stdClass();
$object->foo = new stdClass();
$object->foo->bar = 42;

v::keyNested('foo.bar')->validate($object); // true
```

This rule was inspired by [Yii2 ArrayHelper][].

## Categorization

- Arrays
- Nesting
- Structures

## Changelog

Version | Description
--------|-------------
  1.0.0 | Created

***
See also:

- [Attribute](Attribute.md)
- [Key](Key.md)
- [KeyValue](KeyValue.md)

[Yii2 ArrayHelper]: https://github.com/yiisoft/yii2/blob/68c30c1/framework/helpers/BaseArrayHelper.php "Yii2 ArrayHelper"